Mixing device including counterweight

ABSTRACT

A mixing device for mixing free flowing masses in a container includes: a rotating carrier defining a mixing side, a balancing side disposed opposite the mixing side, and a direction of rotation about the rotational axis of the mixing device; a container carrier for carrying the container, the container carrier being disposed on the mixing side of the rotating carrier and further being adapted to rotate counter to the direction of rotation of the rotating carrier; a housing defining a housing center of gravity and being effective as an active balancing weight for the container carrier for balancing moments on the mixing side and on the balancing side; and a counterweight defining a counterweight center of gravity and disposed on the rotating carrier, the counterweight further having a weight matching a tare weight of the housing. The housing and the counterweight are displaceable radially with respect to the rotational axis of the mixing device on the balancing side of the rotating carrier. Additionally, the housing center of gravity and the counterweight center of gravity are located on a common line extending perpendicularly with respect to the rotational axis of the rotating carrier. Moreover, the counterweight and the housing are displaceable counter to one another by an equal distance.

FIELD OF THE INVENTION

The invention relates to a mixing device for mixing free-flowing masseslocated in a container. The device has a rotating carrier that isprovided on a mixing side with a container carrier for the container.The container which rotates counter to the direction of rotation of thecarrier. The device is further provided on a balancing side with ahousing for an active balancing weight opposite the mixing side, withthe moments of the mixing side and the moments of the balancing sidebeing balanced.

BACKGROUND OF THE INVENTION

DE-OS 42 39 284 discloses a mixing device for free-flowing masses thathas a carrier, a rotating container carrier for a container holding afree-flowing mass, and a housing. The container carrier can be drivenabout its own axis, counter to a direction of rotation of the carrier.The housing serves to receive an active balancing weight in the form ofa free-flowing medium that is matched to the weight of the container andthe weight of the free-flowing mass located in the container.

To mix free-flowing masses having different specific weights, it isnecessary to adapt the active balancing weight. In the process, thevolume of the balancing weight is decreased or increased, or the activebalancing weight, without being changed in volume, is exchanged foranother balancing weight having a different specific weight.

SUMMARY OF THE INVENTION

It is the object of the invention to provide a mixing device with whichfree-flowing masses having different specific weights can be mixedwithout necessitating a change in volume or an exchange of the activebalancing weight.

In accordance with the invention, the object is accomplished with amixing device in which the housing and a counterweight disposed on thecarrier and coinciding in weight with the tare weight of the housing aredisposed to be radially displaceable on the balancing side; the centerof gravity of the housing and the center of gravity of the counterweightare disposed on a common beam extending perpendicular to the axis ofrotation of the carrier, and the counterweight can be displaced,corresponding to the magnitude of displacement of the housing, counterto the direction of displacement of the housing.

To match the active balancing weight disposed in the housing to theweight of the free-flowing mass to be mixed, it is necessary to displacethe housing radially with respect to the axis of rotation. Consequently,the position of the center of gravity of the housing changes. At thesame time, however, the position of the center of gravity of thecounterweight also changes, in the opposite direction, so that the twocenters of gravity lie on the same beam. A common center of gravityformed by the housing and the counterweight likewise lies on the beam,specifically between the centers of gravity of the housing and thecounterweight, and always maintains its position. This ensures that themasses present on the balancing side and the mixing side are constantlybalanced without the weight of the active balancing weight, without thefree-flowing mass located in the container and without the container.

Seen strictly in terms of calculation, only the active balancing weightis displaced when the housing is displaced radially.

The housing and the counterweight advisably cooperate with at least onethreaded spindle disposed to be fixed both axially and against relativerotation, and to rotate freely, on the carrier, with the threaded regionthat cooperates with the housing working in the opposite direction withrespect to the threaded region that cooperates with the counterweight.With the aid of the threaded spindle disposed on the carrier, thehousing and the counterweight can be adjusted simply and quickly.Because of the threaded regions working in opposite directions, thedistance of the housing from the axis of rotation of the mixing deviceand the distance between the housing and the counterweight change whenthe threaded spindle rotates.

The suspension of the housing and the balancing weight on the carrier ofthe mixing device is preferably effected by way of four parallelthreaded spindles cooperating with the housing and the counterweight.The threaded spindles are uniformly distributed at the periphery of thehousing or counterweight, thus achieving a uniform distribution of therotational forces caused by the housing and the counterweight onto thecarrier.

To permit a uniform rotation of all of the threaded spindles and auniform displacement of the housing and the counterweight, the threadedspindles are usefully connected to one another by way of a transmissionelement. The threaded spindles are respectively connected in an endregion to a drive wheel provided with an outer toothing. All of thedrive wheels are connected to one another, so as to be fixed againstrelative rotation, by way of a transmission element, for example in theform of a chain.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is described in detail in conjunction with drawings thatillustrate an embodiment of the invention. Shown are in:

FIG. 1 a side view of a mixing device of the invention;

FIG. 2 a plan view, partially in section, of the mixing device accordingto FIG. 1;

FIG. 3 a sectional representation of the balancing side of the mixingdevice according to FIGS. 1 and 2.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 shows a mixing device serving to mix free-flowing masses locatedin a container, comprising a mixing side M and a balancing side A. Thecontainer and the free-flowing masses located therein are not shown. Arotating carrier 1 extends across the balancing side A and the mixingside M. A drive motor 10, in connection with a gear 11, serves to drivethe carrier 1.

On the mixing side M, the mixing device has a rotating container carrier2, which is disposed on the carrier 1 and can be driven counter to thedirection of rotation of the carrier 1. The container carrier 2 isdriven by way of a drive shaft 12 connected to the gear 11 and anangular gear 13 disposed between the container carrier 2 and the driveshaft 12. A lid 14 is detachably disposed on the container carrier 2.

On the balancing side A, the mixing device has a housing 3 that canreceive an active balancing weight, not shown, in the form of a flowingmedium. A lid 15 is detachably connected to the housing 3.

The housing 3 and a counterweight 4 are seated on freely-rotatablethreaded spindles that are axially fixed to the carrier. The threadedspindles 5 have two threaded regions 6, 7 that work in oppositedirections with respect to one another, each of the threaded regionsextending essentially over one-half the length of the threaded spindles5. The threaded region 6 cooperates with the housing 3, and the threadedregion 7 cooperates with the counterweight 4. When the threaded spindles5 are rotated, the distance between the housing 3 and an axis ofrotation R of the mixing device changes, as does the distance betweenthe housing 3 and the counterweight 4. This means that, depending on thedirection of rotation of the threaded spindles 5, the housing 3 and thecounterweight 4 are moved toward or away from one another. Four parallelthreaded spindles 5, which are essentially disposed in the peripheralregion of the housing 3 and the counterweight 4, serve to displace thehousing 3 and the counterweight 4.

To achieve uniform rotation of all of the threaded spindles 5, thethreaded spindles 5 each have a drive wheel 9 in the center of thecarrier 1, the wheel being connected to a transmission element 8 in theform of a toothed belt. If one of the threaded spindles 5 is rotated,the remaining three threaded spindles 5 simultaneously co-rotate.

The mixing device is conceptualized to be permanently in a balancedstate.

The center of gravity of all masses that results on the balancing side Aof the mixing device is indicated by SA, and the associated radius isindicated by RA. On the mixing side M of the mixing device, theresulting center of gravity of all masses is indicated by SM, and theassociated radius is indicated by RM. The two centers of gravity SA, SMlie on a line perpendicular to the axis of rotation R. The products ofmass and associated radius RA, RM are identical in amount, both on thebalancing side A and the mixing side M.

FIG. 2 shows, in a region of the carrier 1 partially in section, atowing bar 16 supported radially by way of bearing elements 17 on abearing shell 18 disposed in the carrier 1. The towing bar 16 hasexpansion regions that permit the towing bar 16 to be displaced under aprestress. The carrier 1 has four parallel towing bars 16, which permitall of the parts of the carrier 1 to be held together, even at a highrotating speed.

The balancing side A of the mixing device shown in FIG. 3 includes thehousing 3 seated on the threaded spindles 5, and the counterweight 4,with the empty housing 3 and the counterweight 4 having identicalweights and centers of gravity. The housing 3 has a center of gravityS1, and the counterweight 4 has a center of gravity S2. The two centersof gravity S1, S2 lie on a common beam S4, which extends perpendicularto the axis of rotation R. The common center of gravity of the housing 3and the counterweight 4 is indicated by S3, and lies between the centersof gravity S1, S2 on the common beam S4. If it is necessary to displacethe housing 3 radially with respect to the axis of rotation R due tofree-flowing masses (not shown) that differ in degree of mixingdifficulty, this effects a change in the position of the center ofgravity S1 of the housing 3 on the common beam S4. At the same time,however, the center of gravity S2 of the counterweight 4 changes in theopposite direction. Regardless of whether the housing 3 and thecounterweight 4 are now moved toward or away from one another, thecommon center of gravity S3 always remains at the same location on thecommon beam S4.

We claim:
 1. A mixing device for mixing free flowing masses in acontainer, the mixing device having a rotational axis and comprising:arotating carrier defining a mixing side, a balancing side disposedopposite the mixing side, and a direction of rotation about therotational axis of the mixing device; a container carrier for carryingthe container, the container carrier being disposed on the mixing sideof the rotating carrier and further being adapted to rotate counter tothe direction of rotation of the rotating carrier; a housing defining ahousing center of gravity and being effective as an active balancingweight for the container carrier for balancing moments on the mixingside and on the balancing side; a counterweight defining a counterweightcenter of gravity and disposed on the rotating carrier, thecounterweight further having a weight matching a tare weight of thehousing; wherein:the housing and the counterweight are displaceableradially with respect to the rotational axis of the mixing device on thebalancing side of the rotating carrier; the housing center of gravityand the counterweight center of gravity are located on a common lineextending perpendicularly with respect to the rotational axis of therotating carrier; and the counterweight and the housing are displaceablecounter to one another by an equal distance.
 2. The mixing deviceaccording to claim 1, further comprising at least one threaded spindlefixed to the carrier so as to be freely rotatable and having arotational axis extending radially with respect to the rotational axisof the mixing device, the threaded spindle having:a first threadedregion engaging the housing such that a rotation of the spindledisplaces the housing in a first direction; and a second threaded regionengaging the counterweight such that the rotation of the spindledisplaces the counterweight in a second direction counter to the firstdirection.
 3. The mixing device according to claim 2, wherein the atleast one threaded spindle comprises four parallel threaded spindles. 4.The mixing device according to claim 3, further comprising atransmission element connecting the threaded spindles to one another.